Semi-automatic telephone-exchange system



J. L. WRIGHT.

SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM- APPLICATION FILED ocT. 29. 19:5.

8 SHEETSSHEET I 1,383,588. Patented July 5, 1921.

q I w Ill m WITNESSES: IIVVENTOR ham J. L. WRIGHT.

SEMI-AUTOMA'HC IELEPHONE EXCHANGE SYSTEM.

APPucAnon FILED 051229, 1915.

1,383,588. Patented July 5, 1921.

8 SHEETS-SHEET 2.

i k m 20279225555: M W M J. L. WRIGHT.

SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED OCT. 2 I915- Patented July 5, 1921.

8 SHEETS-SHEET 3- J. L. WRIGHT.

SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED OCT. 29; I915.

J INVENTOR WITNESSES. M W /g vJ. L. WRIGHT. SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED OCT. 29,1915.

Patented July 5, 1921.

kWh nu-h (mo 8 SHEETS-SHEET 5- fizz P5555:

44w KLJM/ J. L. WRIGHT. SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED OCT. 29. I915.

8 SHEETS-SHEET 6.

Patented July 5, 1921.

J. L. WRIGHT.

SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM. APPLICATION FILED OCT. 29, 19'5- 1 1,383,588. Patented July 5, 1921.

8 SHEETS-SHEET I.

J. L. WRIGHT.

SEMI-AUTOMATIC TELEPHONE EXCHANGE SYSTEM.

APPLICATION FILED 00129, 1915.

1,383,588. Patented July 5,1921.

8 SHEETS-SHEET 8.

\ N 3 Q Q Q ZZ 172255525: fizz/emin- UNITED STA TES'P'A'TENT OFFICE.

"JOSEPH L'WRIGHT, or CLEVELAND, 0am, ASSIGNOR To WESTERN ELECTRIC.

COMPANY, INCORPORATED, on NEW YORK.

YORK. N. Y., A CORPORATION oE NEw SEMT-AUTO ATIO 'TELEPIT NE-EXGHA GE SYSTEM.

Application filed 0ctober 29, 1915. Serial No. 58,569.

T 0 allwlgom zltmay concern: 7 y p Be itknown that ILJOSEPH L. WRIGHT, acitizen of the United States, residing at Clevelanchin the county of Cuyahoga' and State of Ohio, have invented certain new and useful Improvements in Semi-Automatic Telephone-EXchange Systems, of which the following is a specification.

My invention relates to semi-automatic telephone exchange systems. In systems of this class connections between subscribers lines are effected by means of automatic switching mechanism.

In my invention'certain switches are automatically controlled over the subscribers? lines while others are 'con trolledby operators located at the central ofiice. The switches controlled by the operators are driven in a predetermined manner to contacts of trunks and to contacts of called lines.

The switches for effecting connection with the trunksare termed 'trunk switchesj while those effecting connection with the called lines are termed connector switches.

The trunk switches controlled by the operator are predeterminedly driven to preselected trunks, while the connectorswitches are predeterminedly drivento the called lines. I

The line of the calling subscriber is automatically extended to the operators position by means of automatic selector switches initially controlled over the calling line. After the line is thus extended the operator sets up the number of the called lineon a key-board provided for thatpurposeandalso operates keys for bringing into operation apparatus which automatically selects the trunk to be used. The trunk switches are driven prede-. terminedly to the preselected trunk by means of impulses transmitted over the trunk over which the call originated.

The impulses for selecting the called line are transmitted over a special trunk to the connector switch containing terminals of the called line. "In selecting an idle trunk or connector to be used by the trunk switch the automatic switching mechanism determines the number of impulses to be trans mitted to the trunk switch in accordance with the number of the selected trunk.

Two-wire trunks are used between the trunk selector and connector switches as the test I contacts ordinarily associated with the trunk switches are eliminated by the use of the small number of trunk selecting switches associated with the operators posltlon.

Means are provided for causing the release of the switches over the two-conductor c rcuits and for maintaining a switch in a busy condition as long as another switch is in association therewith. 1 I My invention is illustrated in the accompanying drawings, wherein:

if Figure 1 shows a subscribers line circuit 3nd; controlling apparatus at the central ofce. i

Fig. 2 shows the primary selector and trunk selector circuit. I -F g. 3' shows the connector switch circuit. F g. 4 shows the key-set. control circuit. -Fig. 5 shows an operators key-set switch circuit.

Fig. 6 shows the ciated with an Fig. 7 shows sending device. v

Fig. 8 shows a control circuit and apparatus for selecting an idle connector switch.

F ig. 9 shows the arrangement of the vari ous sheets. i I J Referring to Fig. 1, the subscribers station at A is equipped with apparatus usual control apparatus assooperators key-board. an operators key-board and in common battery systems. The line wires from the station terminate at the central oiiice in a line relay 2 through the contacts relay 1. The line relays are digroups of ten for each one-hun Referring to Fig. 2

shown at'C. The spindle of the switch besides containing wipers which engage the in- I dividual contacts row wiper G tfor selecting the row or group Patented July 5, 1921;

line relay serves to mak'ethe indiin the primary switch .100 The switch W'v is common toa group of one-hundred lines andserves to pick out I an idle primary switch. V

the primary switch is.

is also provided with a l 50 r usual type.

contact of the calling lines. The switch first rotates to pick out the group of calling lines-and then steps vertically until the con tact associated with the calling line is found The tip and sleeve conductors are separated by the condensers 43 and 44. The answering end of these conductors terminate in wipers of the primary sw tch C while the calling conductors extend: to wipersin the trunk selector switch DJ Battery supply is furnished the calling subscriber through the windings ofrelay 23 and theretardation coil 26. Relay. 21 isthestartlng relay and corresponds to the line relay 2 as ;it'-con-,. trols theac'ti'on of the operators key-set switch (Fig. 5); Relay22 is the row test relay, while 24 is the individual test, relay,

Relay 25 i's'oper'aftedwhen the key set switch picks out, the primary trunk. Relay 28. is

the interrupter relay and operated when either the rotary or vertical magnets {of the switch C are energized. The circuits of [these magnets are normally completed through'the back contacts of this relay and so, therefore, whenever it is operated the magnet circuits are broken. The action set up between the magnets and relay causes-a vibrating effect which causes the EfOl'Il'lGI to ual contact in the group.

' Battery-supply is furnished the called s ubscri'ber ,fthr'oug'h the windings of relay 357 andretarda'tion coil 358. Belay 355 is the V ringing'relay operated intermittently by the commutator I, while"366 is the busy testrelay. Relay 351 is controlled from the pri-' Imaryftrunk andis used for rendering the V connector switch busy and also for restoring the-same in case the called subscriber fails l tons and are nsed for associating an Idle to answer. h

Relay 390 is 'a "slow acting relay of the Referring to Fig.4, switch Yicorresponds to and performs the same functions as the switch (Fig. '1) and. serves to pick out an idleikeyset switch. Referring to 'Fig. 5, he key-set switch :M

is similar to and acts in the samemanneras the primary switch C. 168 is the row wiper connected to its row test relay 153. 154 is the individual test relay, while relay 156 is the signal relay and operated in series with "relay 25 (Fig. 2) when the primary trunk is selected" Relay 152 is the starting relay corresponding to relay 21 (Fig. 2). 7 Relay 155 is-controlled by the answering button 7 the sending device.

248 and when energized connects the operators telephone set to the tip and sleeveconductors' of the trunk; 7

Referring to Figs. 6, 7 andj'8, an operators keyboard, sending device and controlling circuits are shownJ'Th'e key-board consists o'fthree rows of buttons, each row compris-- ing ten buttons. The first two rows'of buttons R and S are used in conjunction with the sending device for transmitting a predetermined number of impulses :to' the-con nector switch; No.1 button of each row is 7 connected to the contact 'on the sending device operated by a cam 232; No. 2 button of each row is connected'to the contact operated by cam233. The corresponding but tons in-;each roware connectedto similar contacts int'he sending device. The contact controlled by cam 232 is closed just long enough to maintain relays 202 203 and 256' (Fig.: 3-6?) energized, while one impulse is being transmitted by each of the commutators 242 and 243 of the sending device. If No.

10 button is depressed thenthese relays will be controlled by cam 241soasto allow f'ten impulses 1 to be transmitted by each of the commutators 242 and 243. The contacts o-f commutator 243 are connected to normally open contacts of relay 202, while-contacts of J commutator 242 are connected to normally open contacts of'relay's 203 and 256,

When these relays are operated the'impuls'es are directed ever thetip and sleeve sides of the trunks for controlling-the connector switches and-trunk switches. The impulses are transferred in -grou-ps to the tip and sleeve conductors in certain order for oper ating the switches by means of *the shifting.

. switch N;

The buttons in the rows 'R and S are of the usual lockingand indicating type and so arranged that when one 7 button of ,a certain row is depressed it will release "the button formerly depressed. The buttons in-the row V areof anon-locking type. When anyone of these buttons is fdepressed it. will operate an associated trunk relay. These {buttons 1.

are termed g'roup buttons or trunk but one .of'a group of connector switches with =1 :havejillustrated but two of these 7 trunk relays, 200 and 201, bu in reality therefwould-be ten.

In order to select an idle connector switch 7 V in a group containing the line'of thecalled Y switches of the group. When=an-idle cone nector switch of the group isselected then 5. nector is selected and serves to'connect the to which the resistance coils are shown' conten impulse control wires from the segments of the sending device to contactsin the portion 310 of the switch O.- This portion of the switch performs the same functions as the buttons in the rows R and S, namely, to proper impulse wire select and connect the to the common. conductor 211.

As each connector switch utilizes two. con

tacts in the switch 0 then for the ten switches in the group there will be twenty contacts in the switch O. v

The ten impulse wires are connected in order to contacts in the portion 310 corre sponding to the contacts in theportion 312 nected. v I have shown but five of the ten impulse wires connected to contacts of relay 320 and but ten contacts in the switch 0. Y If the'connector switch selected is No; 1

then No. 1 impulse control-wire will be con'- nected through the portion 310 of the switch and through the medium of the shifting switch N to the winding of relay 256. When- Zthis relayv is operated the impulses corresponding in number to the unlts digit of se-' lected connector switch are'transmitted over the sleeve conductor to the trunk switch D.

The tens impulses corresponding to the tens 35 digit of the selected connector for operating the trunk switch'are connected to the t':) conductor extending to the trunk switch by means of relay 203. The impulses foreperating the connector switch are determined 10. by-the buttons depressed in the rows R and S and are transmitted overthe trunk conductors selected by the switch 0.

From the foregoing it will be noted that the impulses for operating the connector -.switch are predetermined and directly uns der control of the operator. The impulses for operating the trunk switch are automati .cally predetermined by the trunk relay op erated by one of the trunk buttons in the FY row V and according to the position assumed by the switch 0.- The connector switch is first selected and impulsesin-number corresponding to the number of the connectordirectly to the: causing it 'to effect connection I switch are then transmitted with the selected connector 'switch.

After the impulses are transmitted the switch M (Fig. 5) is automatically restored and in readiness to be used for anotherycallk" Referring in particular to-Figs. 6 and 8,

the switch 0 remains in association with the selected connector switch during two steps, or while the wipers engage two sets of contacts. The switch stops in one position'after; having selected the connector switch, and 1s then shifted to the second position or contact in order to allow the impulses to be transferred fromthe rotary to the vertical The primary switches, key-set switches,

trunk switches and connectorswitches are of the type shown in Patent No. 977,586, December 6, -1910 to C. HQ North. These switches first rotate and bring their wipers in line with proper groups of contacts and then step vertically, causing the wipers to en age individual contacts in the row.

filther details of the circuit and apparatus will be best understood in tracing a call from a calling. to a called subscribers line.

The subscriber at station A upon removing his receiver closes the circuit of the line relay 2 in series with the group relay 3. This latter relay operating closes the circuit of'relay i which in turn connects ground to one terminal. of the relay 5 and also closes the circuit of the stepping magnet 7 The stepping magnet operating closes the circuit of relay. 6 which in turn opens the circuit of the magnetitself. causing it to vibrate and steptheswitchWJ This switch will'continue to rotate until an idle primaryj switch such as shown in Fig'. 2 is foundj As soon as such .a switch is founchthe relay 5 is placed in series with relay :21, (Fig. 2) by thefollowing path: ground, contact of relay 4, 5, 18, W, .14, 21, 70, contact of: relay 24c to battery B. The relay 5 operating opens the circuit "of the magnet? bringing the switch W to rest.

Relay 21 operating closes the circuit of the rotary stepping magnet 81 by the following-path: battery B, 80, back contact of relay'24, 71, contact of relay 28, back contact of relay 22, 31 to ground. The operation of magnet 31 causes the switch C to rotate until the wiper 64 reaches the busy rowcontact. 1

The wiper 64 is carried on the same spindle with the wipers 63 and 65,'and while the switch, is rotating the wiper 64 passes over contacts leading to the group relay 3. As

There are ten sets of individual contacts arranged in vertical rows associated with 7 therefore that after the switch :picks out the.

each row contact and which the wipers-63 and 65 respectively engage. It follows group in which a line is calling, it will afterward-step vertically until the wipers enga e the contacts of the callingline.

s soon as the row contact 1s found, the circuit of relay '22 is closed as follows: battery B, 80, back'contact of relay 24, 71, '22,-

64, 13, contact'offrelay 3, to ground. The

relay -22in operating disconnects. the rotary magnet 31 and inits place connects thever tical magnet .30, thereby causing the switch to step vertically until the "busy individual test contact is found. Assoon -as .such :a contact is found the circuit of .relay 24 is closed as follows: battery B, 24, -68, contacts'of relay22, 67 11, contactsof relay 2' p to ground through the contacts of relay 1..

disconnects relay 24from the, wire'67 and connects it instead to wire 66, thereby r so Relay 24 operating'o'pens the wire 71 and disconnects relay 22 which in'fallin-g iback placing relays 24 and '1 in series. The operation of relay 1 -disconnects the line relay 2 and the group relay 3. Relay 24 connects battery to. the windings of relays 23 and 25 and the'falling-back of relay 22 the wire 7 9 to relay 130 and also places battery to wire 62 which is connected to the individual test contact of the key-set :switch.

(Fig; 5

Relay 130 closes'thecircuit of the stepping magnetof the switch Y through the ;nor-' qmally closed contacts of relays 13 1, 132.

i .lay 1-52'by The magnet in operating :closes .the'icircuit of the interrupter relay. 134, thereby .causing themagnet to vibrate and the switchto rotate until an idle key-set switch is found;

When such a switch is found, as's'hown in Fig. '5, relay 131 is placed "in series with rethe following path: ground, contacts of-relay 130,131, 138, Y 140, 152,195, 196,

this latter :relay operates, ground is placed on the wire 138, thereby shunting relay '131.

This direct :ground placed on wire 138makes the wire 140 which is multipled toother Y switchesbusy. The operating of relay 132 V also places-'ground-on the row wiper of the ground,.139, Y, 141, to the row contact. V The. operation of relay 152 connects -set switch .by the following path:

key

. ground to the rotary gmagnet. 165 through the :back contact of relay 163 causing the switch M to rotate. This switch will ro- Relay 21, when first actuated, places" battery on 197 toba'ttery B through the operators 'jack 400. Relay 131 operating'placesbatter-yxon wire 136 to'relay 132. Aszsooncas.

are multiPled:

. 1.,asasss tate until the'busy row contact is found, whereupon the circuit of relay 153 will be closed as follows: battery B, contacts of relay 152, 176, 153, 171,168,141, 13.9,1contacts of relay 132 to' ground. The 'keyset switch M operates in thesame manner. as the primary switch .0 (Fig. -2i); Relay 153 disconnects the rotary" magnet 165 and connects in its place the erti'c'al magnetr164,

thereby causing the switch to step yer-tr cally until the busy individual :test contact is found. The finding f this contact closes the circuit ofrelay 154 as followsz ground, 7

154, 172, 62, 80, contactsof relay 21 to abat tery B. Relay 154 disconnects relay 152, thereby cutting off .the Evertical magnet :and. oausing-the key-set switch .iJOqIGSt on contacts leading-tothe calling primary trunk.-

1 Relay 152 becoming deenergizled opens the circuit of relay 153 and this latter relay in falling back places relays 156 and 25 series by the following path: ground, back contact of relay 153, 175,- back contact of relay 157, 102, fcontact'of relay'155, 156,

193, 169 59,25 to battery B through the contactof relay 24, ,Trhe'loperating of relay 225 {(Fig. 2) disconnects relay 21.,and also relay 5 (Fig. 1). The releasing lofrelay 5 frees the switch allowing it to,v

pick out other primary switches. ,Relay 156 operatin Iplaces :battery won-wires 181 and 183 causing light; V Y

. As soon asre'lay121 in Fig. 2 became dis connected battery was removed from'the individual test contact zoffthe'keyset switch, thereby allowing relay 15410 fall back. Helay: 21 ,also-v Lreleases relay- 130, thereby restoring relay 132-:so :as'to allow the switch. Y:.to be :used by other trunks inpickinglout key-set switches. I E a In the present'instance I ?have provided ten primary switches as shown in Fig. 2 for each one hundred lines- Each group of ten primary switches is in turn provided with one LY zswltch for picking out idle; Ekey-set switches.v The percentage and grouping of trafficconditions; 7 v

'llhe'wire 141 leading from the Y switch" to the row contacts of the key-set switch is not multipled. The Y switch ,picks out anidle key-set switch and;this places ground on'the row, contact of the selected switch and these row contacts are not multipled. This arrangement prevents interference between other Y switches'and'also between the" the trunks'cand lines canwbe' 'va-ried to suit one hundred lines and picks out a group the lamps 234 and-244 to, j

key-set switches. ,Inlno case-is groundplaced onmore than one row contact of any .key-

of primary switches, and in this case the row contacts of a'cgroup of primary switches The lightingof the lamps 234 and 244 notifies the operator of a call, andshe then presses button 248 operating relayyl55. The operation of this relay connects her telephone set across the'trunkwires, disconnects relay 156, thereby extinguishing the lamps 234' and 244. -The disconnecting of relay 156 also opens the circuitzof relay 25, (Fig. 2) which in falling back closes the tip and sleeve conductorsof the trunk, allowing the operator to converse withjthe calling subscriber. 1 [v i The operator after receiving the number from a calling subscriber depresses but: tons in rows Rand S corresponding to the tens and units digits; After depressing these buttons the operatordepresses a button in the row V cor'respondingto the-hundreds digits of the called subscriber; vIn

the present-instance we will assume that the firstbutton is depressed; the depressing of this button completes the circuit of relay 200. The operation of this relay connects the winding of relay 204 and-the winding ofv relay 300 (Fig. 8) in series with the resistance coil 301. ,Relay 200 remains locked to ground. through the back contacts of relay 206 and the button 208. Relay 300 becomes energized but relay 204 is not operated due tothe high resistanceof coil 301. The operation of relay 300 completes the circuit of the stepping magnet 304 of the switch 0 by the following path: ground, contacts of relay 300, contacts of relay 302, winding of magnet 304 to battery B. The

operation ,of-the magnet completes the cir- I cult of the interrupter relay 302 by the following path: ground, contacts of relay 300, 314, contacts ofj'relay 305, 315,- 316, Winding, of'relay 302, to battery B. The

operation of relay-302 opens the circuit of the magnet 304 and the magnet in restoring again allows relay 302to drop back. This action between the magnet and relay. 302 causes the switch 0 to rotate until an idle switch is selected. As soon as such a switch is selected, such as shown in Fig. 3, then;

relays 303 and 350 areplaced in series by the following path: battery B, contacts of relay 300, 326, winding of relay 303, 325, 312, 324,

winding of relay 350, contacts of relay 490',- 37 7 cam springs 370 to ground. The opera-- tion of relay 303 completes the circuit; of relay 305. This latter relay in operating connects battery directly between the winding of relay 303 and the testing switch wiper 312, thereby rendering the contact uponwhich the Iwiper rests busy against other calls. The efl'ect otbattery being connected in this manner shunts relay 303 causing it to restore, but relay 305 remains locked to ground through the contacts of relay 300.

Theoperation of relay 305 also connects ground between the winding of relay 300 and the coil 301,.therebyshunting out the operator that latter'relay disconnects ground from the looking contacts of relay. 155 and connects ground to the wiper 169, thereby operating relay "25, Fig. 2. The operation of this relay 25 severe the tip and sleeve conductors and also causes the operation of relay 42. The operation of this latter relay connects the relays 27 and 528 respectively to the conductors 54 and 53. The operation of relay 204 after an idle switch is selected, also completes the circuit of the stepping magnet 205 of the switch N so that it can be operated by the springs controlled by the cam 231 of the sending device. Assoon-as the contact springs controlled by this cam are operated then the magnet 205 is operated'and after the con tacts are broken the switch wipers 250, 251 and 252 leave the first set of contacts and engage thesecond set. It will be noted that the windingv of relay 204 is connected to battery through normally closed contacts of the magnet 205 and-to battery through the contact upon which the switch wiper 252 normally rests. After the switch'takes the first step then battery connection to the, relay'204 is controlled wholly through the contacts of the magnet 205. 100

After taking the first ste the common wire 258 of the row buttons 5 is connected directly to the winding of relay 202 through the switch Wiper 250 and the common wire 401 of the trunk relays is connected directly to the winding-of relay 203 through the wiper 251. 'Relays 202 and 203aremaintained energized for a certain length of time, depending upon the button depressed in the row and according to the trunk relay operated. e

' The connector-switch E is operated by 7 means of impulses from the commutator 243 while the trunk switch D is operated by means of impulses transmitted by the commutator 242. r c

After the wipers of the switch N engage. the second set of contacts relay 202 is main-; tained energized for le'ngthof time depend ing upon which button is depressed in the row R. Relay 203 is likewise held energized for length of time depending upon which .7 cordingto the button 7 i impulses "2'00, 212," 311,323, winding of relay sanctittery They'ope'ration of this relay, ac-

ca'uses acorresponding operation of the rotary mag-net362 by the following path:

rotate to the proper position. 7 7 from the commutator 24:2 cause the operation'o-f the rotary relay 27,-of the 'trunl': switch D by the followingipatha relay 208,261,- r 7 more of :1-e1aY ground; commutator 242 260, contacts of 5562', 'wipercl67, 61, 54: con- 42-, winding of relay-27 to batteryB The operation of magnet 48" in '7 responsetothe operation of relay 27 causes its winding by'the operation of'the contacts.

the switch D to assume a position withits wipers'in lin ing to the preselected connector switch.

7 The'relay' 203 for regulating thenumber of impulses tote transmitted has its circuit completedby the following path: ground, contacts controlled by segment 232, 400,,con-

200; 01; second contact in the the switch N, 265,-wi'nding *After -the termination of this first group of twosets of impulses the circuit of the magnet 205 of the switch N has its circuit completed bythesprings controlled by the cam 23 1 en the sending device. While the magnet circuit is'closed the circuit of relay 204k is broken as batteryis disconnected from of iiiagnet- 205, The opening of this relay circuit ca'us'es its deener'gization'as well as the deenergization of relay 300 with which itifs in series. v the signal lamp 207 to be momentarily ex-' tingu'ished. Relay 30051-1 restoring removes i groundfrom the 'win'din'g of the magnet 304 thereby causing'the wipers of the switch to take one step en age the second set of contacts associated with the selected connectors'witc'h'. In taking this step relay 352 is disconnectedfrom the trunk: con j fductor 212 and relay 353 connected in its 5-0 place.

As soon as magnet 205 by liyered {the magnet restores and causes'the 2'56 -by the following-path; round, contacts I wipers "of the switch N to engage'the third;-

set of contacts thereby connecting the com monc'onduet'or' 257 "ofthe row of buttons the winding of relay 202. The switch in" thesegmentsj237) to the winding of relay I gne fft, 237 contacts of relay 820, contact of portion 310 of the depressed in the row 7 with a row of contacts lead-' I tion of that" trunk by .another switch 10,

, Relay 204: restoring causes the impulse transmitted the the cam 23 1 has been de- 'assumingthis position also connects an :impi'il'se' control wire from one ofthe' seg -"nieii'ts'ofjthe 'sen'ldingmachine (which we will assume to be the conductor connected to restoration of switch M switch 0, 211, contacts of relay 200,.403, portin251 of the switch N,404, winding of relay 256 to battery B. i

The momentary restoration of relay 300 does not release relay 305, as it is made slow acting'for this purpose? The:-,wiper 312 moving from the contact which is directly connected "to thejw-inding of} 350 "still 'm'ain' tains that relay energized as the next con tact in the switch'is connected to' a contact V 350 whichengagesa cooperating of relay 7 contact leading to the winding of the relay itself." 'With -this method of control the relay 350 isinitia lly energizedover thefirst test contact, associated-rwith ;a-' connectorf switch :an-d' is thereafter controlled over the second'contact'. The operation o'frelay 805 maintains 7 direct" battery connected to the wiper while engaging' 'ei'ther of these two contacts thereby preventing" the selecthe operation of relay 305v preventing: the

operation'iofthe-interrupter relay 302.1-1

After the switch N engages the-third set i relay 353' of the switch; E; The operation; of this relay'c'auses' a corresponding opera-p tion of thefvertical magnet 3% thereby caus ing the switchfE'to" step vertically and wipersfengage contacts of the-called line. While relay 256 isenergized impulses are transmitted 'overthe; sleeve r conduct'or through the switch wiper 167 of the switch The'number of impulses transmitted to the relay '52 8 wil-l correspondfto' the position depending upon the segment -M to thevertical re1'ay5'28"ofthe-switch'D;

assumed by the switch IO in select1ng the switch E; The impulses-are 'repeated 'bythe relay 528 to the magnet 49 thereby "causing the switch; D to engage contacts leading di-- rectly to the preselected switch 1 After this last group of impulses have u been transmitted to the switch'es D and E the circuit of: the stepping @ma'gnet;205 er the switch N is again completed by --rnea11s' of an impulse transmitted by the cam 231.

After this impulse has been deliveredthe wipers of the switch N step totheir fourth or normal position. 1nm'oving to this po 'sition the wiper 252 sweeps-over the contact 2707 thereby momentarily ener izing relay 206. The operation of this relay removes ground jfr'omi the locking contact of relay:

200 thereby disconnecting the sending device from the switch it and falso completes the circuitof release magnet 166 causing the V The restoration of relay 200 severs the connection between relays-204 and 300.- Thelatter relay Jinirestoringi'removes ground from thewlocking contact of relay'305 and after a short time interval this relay restores and places the switch 0 in condition to be used in: extendingother calls; The restoration :ofrelay 305 removes battery from the test, wiper 3 12 andfthe restoration of relay 300 .removes battery from the winding of relay 303' thereby opening the circuit of relay 350. .This relay min-restoring opens the circuit of the slow acting relay 390. Be-

fore relay 390 restores ground is connect-- ed to'the winding-of relay 352 by the following 'pathzground; contacts of relay 350, contacts of-relay 390, winding of relay 352 to battery'B. The operation of relay352 at. this time while the switch wipersare resting on. contacts of the called iline connects the test relay 366 to the test wiper 373. In casethe relay 366 willbecome energized and'connect calledsfor line is busy the ground directly to the winding of the release magnet 39l thereby causing the 'restoration of V a relay 366 the switch The operation of also connects a suitable busy tone signal to oneof the trunk conductorsnoti'fy ing the ca'llingsubscriber that the calledfor' line is busy. In case' the called-for line is not busy', then relay 366 :i's not affected and the connection remains extended to the- Relay 356 is placed in'series with the'cutofi' relay of the calledline through the test wiper 373. The operation of the cut oif re lay disconnects'theline'relay and the opera tion of relay 356 completes the circuit of the ringing'relay 355by'the following path: battery B, contacts of relay 356, 3995 contacts of relay 359, winding of relay 355, commutator I to ground. The operation of relay 355 severe the tip and sleeve conductors and connects generator G to the called line. W hen the called subscriber removes his re ceiver tip relay 357 is operated thereby completing the circuit of relay 359. I

After the called subscriber replaces his receiver relay 357 restores and completes the circuit of the release magnet 391 by the fol-f lowing path: ground, contacts of relay 357, 383, contacts of relay 359, winding of magnet 391 to battery B; The operation of this magnet causes the restoration of theswitch and when the switch is fully'restored cam springs 370 are operated thereby disconnect position, v v

The calling subscriber replacing his receiver causes the deenergizati on of relay 23. -This relay restoringcomp-let'es the circuit of the release magnet 32 by the following path; battery'B, contacts of relay 25-, 76, contactsof relay 21, 7 5,'cain springs 39,74,

mag-

'CandD lng' ground from the locking contact of relay 359 causing it to restore to its normal net 32 to ground. The operation of this magnet causes the restoration of the switch C and when theswitch is fully restored cam springs 39 are separated and break the circuit of the release magnet 32. While the release magnet is energized ground is connected directlyto the tipcconducto-r' 54 by the operation'of'the contacts associated with the magnet. This ground connection causes the operation of relay 351 associated with the connector switch (Fig. The operation of this relay causes thedeenergization of relay 490 so as to render the connector switch available or selectable for the other calls.

Relay 490 was operated at .the first impulse received by the relay 3'52 from the sending device. The operation-of this relay disconnects the windin of relay 350 from the cam springs-370. s-lonq as relay 490 is operated the switch E cannot be again selected by thesw itch 0. Relay 490 will remain energized until the calling subscriber causes therelease of the switch C as just described; J r p l The restoration: of the switch G completes the circuit of'the'release magnet 554 ofthe switch .D by the following ath: ground, cam springs 57 of the switch to battery B. Thexoperation of'magnet 554 causes the restoration of the switch D and when it has fully restored the cam springs 57 separate and open the circuit of magnet 554. In casethe called-for subscriber 'does not answer then the calling subscriber replacing his'receiver causes the release of the switches in the manner'described and also causes theoperation of relay 351. The operation of relay 351 besides unlocking relay 490 completes the circuit of relay 359 by the following path: ground, contacts of'relay3 57, contacts ofrelay 351 379, winding of relay 359to batteryB. The operation of relay'359 completes the circuit of the release magnet 391 by the following path: ground, contacts of'relay 357, 383, contacts of relay 359, 380, winding of -Inagnet'-391 to' battery The operation ofthis magnet causes the restoration of the switch E, which upon fully restoring operates the 'cam springs 370 and causes the restoration of relay 359. g It will'be noted that the called subscriber retains control of the release of the switch E as longas' the tip relay 357 is energized and thegonly effect of the operation of relay 351 under these' conditions will result in the restoration of relay 490' to partiallycomplete the circuit over which the switch E may be selected by the switch O. 'VVhen the called subscriberreplaces his receiver and causes'the releaseof the switch E then the circuit over which thefswitch is selected will be completedthrough the cam springs 370. p The switch E cannot be selected after once being operated unless it has fully restored and the relay 490 also restored when the calling subscriber causes the release of the switchC. 3

Ihave illustrated and described a system and arplurality of connector switches.

employing a plurality of trunk switcheslll) each operator being provided with two rows of buttons for controlling the operationoi the connector switches and a row ofxtrunk buttonslfor causing the selectioniof a particular'connector in a group, the selection of v which automatically determines the number of impulses to be transmitted to the trunk switches D;'

thus described invention what I desire to secure by. Letters Patent is: 1

i1.'-In a telephone exchange system com-- prising subscribers lines, talking trunks,

, c automatic switches for uniting said lines and talkmgtrunks into conversational clrcults,

a control trunk, separate trunks, means 7 whereby a calling subscriber'may communl cate his order to an operator oversaid con- I trol trunk, means whereby an operator may directly control the operation ofcertain of saidiswitches overa trunk separate, from said controltrunk, andaddltionalf means; for con-1 trolling other of said switches over said control trunk;

' trol trunk, means whereby an operator may controltrunk, releasing means forsaid conoperable after the operation of said switches: telephone exchange system come: prisingcallingand called subscribers lines;

a primary trunk, means for causing said pridirectively control the operation ofcertain- V of said switches-overa trunk separate from said control'trunk, and additlonal means for j controlling other of said switches .over said trol trunk, said'releasing means rendered 3; Ina

" mafry trunk tobe automatically connected with V fiacalling line upon initiation'of a;call,a trunk' V to'thecalled line, additional meansj for diswitch permanently associated with said pri-' mary trunk, a connector switch for connecting with the" called subscribers lin'es, an operators position andorder trunkleading thereto, circuits separate fromsaid 1 order trunk, an electrically controlled selector switch at the exchange, 'means for initiating travel thereof to connect said primary trunk and ordentrunk in response tothe operation: 7 of said selector switch, operators means for transmitting directive currents over; a' ci'r-;- cuit separate from'said order'trunk'tofsaid connector switch to establish "a connection rectivelyj operating said trunk switch to ex- I i tend the connection from the calling line to said connector switch;

means .for causing: said primary switch to nector switches and the called line, .addi

r 4. Incaftelephoneex'change system, calling and called subscribers 'lines,:..tennina1sthere+ for at the exchange, a primary trunk comprising a primary switch and a trunk switch,

be automaticallyiconne'cted with a calling line upon the ninitiation ofa call, connector switches for"effectingi connection' with terminals of a called-line, an operators position and order trunk leading thereto, circuits separate from saidorder trunks, operators means for transmitting directive currents over a clrcuit. separate. from said order trunk to establish "a-connection between; the cone 7 tional operators means for transmitting di-:

rectiveicurrents over said order trunk to establishl a-.'connect1on w-cfr om .the- 1trunk' switchesto said connector'switches. f 5. Inca telephone exchange system' including a'callingsand a-called subscribers line, terminals therefor at 'thefj'exchange, a'link circuit comprising a primary :switch and'a trunk switch,- said primary switch .adaptedto V I be automatically connected with a calling lineuponftheinitiation of a call,v a connector switch forjeff lcting connectionwith a called line, an operators positionand order trunk leading ther'eto',- separate circuits, operators means for transmitting directive currents over a circuit separate from said order trunk 1 to cause said connector switchto efi'ecct GOD-: nection with'the called line, means initially controlled-by the operator for selectingsaid connector switch, additional means controlled 7 V by the-selection of said connector switch for predeterminedly driving; said trunk switch" to effect connection with said connector S it hi 6 In a telephone exchange system compris ing calling and called subscribers lines,.-a link circuit,-means forcausing said link cire cuit to be automatically associated with a calling line upon theinitiationofa call, con

nector switches for'eflect'ing connection with the called lines, a trunk switch permanently associate d'with said link circuit for effecting connection withsaid. connector switches, an:

operators position and an order trunk lead, ing thereto, trunk, 'means for automatically extending the link circuit to said position, means con;

trolledatsaid position for selecting an idle. V

connector switch over a circuit separate'from said order-trunlqmea'ns associated'with said positionfor .directively driving'the selected connector switch to a called line, means 0on trolled in the selection of the idle connector switch for clirectively driving th'efsaid trunk switch-to the preselectedconne'ctor switch. i 7

7. In a'telephone exchange systemcom pris'ingijcalling and called subscribersclines,

a;lin1 r:circuit, meansforcausing said link;

ClI'CHltftQ'be automatically associated-with:

a calling line upon theinitiation of a call, V

circuitsseparate froIn said order" 115 connector switches for. effecting connection with'the called lines, a trunk switch permanently associated with said link circuit for effecting connection with said connector switches, an operators position and an order trunk leading thereto, circuits separate from said order trunk, means for automatically extending the link circuit to said position, means controlled at said position for selecting an idle connector switch over a circuit separate from said order trunk, means associated with said position for directively drivmg the selected connector switch to a called line, means controlled in the selection of the idle connector switch for directively driving said trunk switch to the preselected connector switch, said connector switch and said trunk switch being driven simultaneously to effect said connections. 7

.8. In a telephone exchange systemcomprising callingand called subscribers lines, a link circuit, means for causing said link circuit to be automatically connected with a calling line upon the initiation of a call, a trunk switch permanently associated with said link circuit, connector switches for effecting connectionswith the called lines, an operators position, means for associating said position with said link circuit, means controlled at said position for automatically selecting an idle connector switch, means at said position for causing said idle connector switch to effect connection with a called line, means controlled in the selection ofsaid connector switch for causing said trunk switch to eifect connection with the selected connector switch.

9; In a telephone exchange system, comprising calling and called subscribers lines, a primary link circuit, means for causing said primary link circuit to be connected with a calling line, a trunk switch permanently associated with said linkcircuit, connector switches for effecting connection with the called lines, an operators position, an order circuit extending from said link circuit to said position, over which the order of the calling subscriber is taken, means asso-, ciated with said position for selecting an idle connector switch, means controlled in the selection of the idle connector switch for causing said trunk switch to efiect connection with the selected connector switch, additional means at said position for causing the selected connector switch to effect connection with a called line. Y

10. In a telephone exchange system comprising callingand called subscribers lines, a primary link circuit, means for causing said primary link circuit to be connected with a calling line, a trunk switch permanently associated with said link circuit, connector switches for effecting connection with the called lines, an operators position, anl order trunk extending from said link circuit to saidposition over which the order of the calling subscriber is taken, circuits separate from said order trunk, means at said position for selecting a connector switch over a circuit separate from said order trunk, impulse controlling mea nsat said position, means under control of the operator for connecting said impulse controlling means to said selected connector switch for directing it to the called line, means controlled in the selection of said connector switch for automatically causing said impulse controlling means to be associated with said trunk switch over said order trunk to direct nector switch whereby a conversational cir-v cuit is established from the calling to the called subscribers line.

11. In a telephone exchange system comprising calling and called subscribers lines, a primary link circuit, means for causing said primary link circuit to be connected. with a calling line, nently associated with said link circuit, connector switches for effecting connection with the called lines, an operators position, an order trunk extending from said link circuit to said position over which the order of the calling subscriber is taken, circuits separate from said order trunk, means at said position for selecting a connector switch over a circuit separate from said order trunk, impulse controlling means at said position, means under control of the operator for connecting said impulse controlling means to said selected connector switch for directing it to the called line, means controlled in j the selection of said connector switch for automatically causing said impulse con-. trolling means to be associated with said trunk switch over said order trunk to direct it to the selected connector switch whereby a conversational circuit is established from the calling to the called subscribers line, means for automatically disconnecting said operators position from said link circuit and from said connector switch after the establishment of said conversational circuit.

12. In a telephone exchange system comprising calling and called subscribers lines, a link circuit, means for causing said link circuit to be connected with a calling line, a trunk switch associated with said link circuit,-connector switches for effecting connection with the called lines, an operators position, an order trunk extending from said link circuit to said position over which the order of a calling subscriber. is taken, impulse controlling means at said position, a distributing switch controlled at said position for automatically selecting an idle connector switch, said distributing switch being provided with a plurality of contacts, means controlled through said contacts for connecting said impulse controlling means to it to the selected cona trunk switch permasaid order trunk for, causing said trunk switch to select the idle'or selected connector switch, and means atisaid position for connecting said impulse controlling means to the selected connector switch for causing it .to ,efi'ectconnection with a called line.

13. In a telephone exchange system comprising calling and called subscribers lines,

a" link circuit, means for causing said-link circuit to be connected'wlth a calling llne, a;

trunk switch associated with said link circuit, connector swltches for effecting connection with the 'called lines, *an operators position provided-with an impulse sending device for controlling the operatlon of said switches, a,

distributing switch at said po sition provided with a plurality of contacts,

means controlled over certain of said contacts for selecting an idle one ofsaid connector switches, means controlled through other contacts of sa1d. distributing switch:

for connecting sa1d impulse device 'to said trunk switch for causlngiitto efi'ect connec tion with the select connector switch, and

means controlled at said position for con necting'saidimpulse device to'the selected connectorswitch for causing it to effectjconnection witha called line.

I IQIn a telephone exchange system comrisin callin and' called subscribers lines D D 7 a link, circuit, meansfor causing saidvlink connected to a calling line, a; trunk switch associated with'said link cirvcuit, a plurality of groups of connector circuit to be switches for effecting connection with the called lines, an operators position provided. with an impulse sending device, means 'at said position for selecting a particular group of said connector switches, and additional means for automatically selecting an idle connector switch in the group means con trolled 1n. selectlng an dle conn'ector SWltCll' -'15. In a telephone exchange system eluding a calling and a called subscribers l ne, a link circuit, means for causing sa d llnk circult to beconnected with the calling with said link circuit, a plurality of con nector switches for efiecting connection with the called line, an operators position, means associated with, said position separate from said trunk switch for automatically selecting an idleone of said connector switches,

additional means associated with said posi-,

tion for operating the selected connector switch to cause it to efiect connection with the called line, releasing means for said connector switch, and additional means associa trunk switch permanently associated ated with said position-for causing the trunk switch to efiect connection with the idle connector switch after its selection, and means controlled over said trunk switch for actuating the releasing means of said connector switch. I

16. In a telephone exchange system including a calling and'a called subscribers line, afplurality of connector switches, means} '75 with the called line, releasing means for said for causing said switches to effect connection switches, atrunk swltch for effecting con nectlon with sa1d connectors, means sepa-W rate from said trunk switch for selectingoan idle one of said connector switches, and means controlled over said trunk, swltchfor thereafter actuating thereleasing means-of said' 'selected'connector switch.

17. In a telephone exchange, system, the

combination with-acalled line, 'aplurality of connector switches for effecting connection therewith,atrunk switch for effecting con? nection with sa1d connector sw itches, nieans separate from sa1d trunk switch for selectmg an 1dle one'oit said 'connector'switches;

and means controlledby said connector switch 1n effecting connectionwith thefcalled line to render said switch unselectable, means controlled by saidtrunk switch for again rendering said. connector switch selectable;

18. In a telephone exchange system, the

combination with a calledsubscribers,line,

of a plurality of connector switches -for effecting connection therewith,- means for selecting an idle one of said' connector: sw1tches,-'a trunk swltch, means for causingsaid trunk switch to be associated with the idle connector switch after its selection, means controlled in' the operation of the selected connector switch in effecting con-- nectionwith the called line for rendering it unselectable; means controlled over said trunk switch for thereafterrendering said connector switch selectable. i

19. Inca tele hone exchangefsystem, in-' cluding a calling and a called subscribers line, a plurality of 'connecton svvitches, means fforf causing said switches to effect connection with the called line, a trunk switch, means for selecting an idle connector, switch,me ans controlledlin the selection of said connector switch for causingsaid trunk switchto effectconnection therewith, means for causing theconnector switch to effect connection withthe called line, means controlled in enacting connection with .the

called line to render saidconnector switch a trunk switch permanently associated with said link circuit, a plurality of connector switches for effecting connection with the called line, an operators' position, means controlled from said position for automatically selecting an idle one of said connector switches, means thereafter controlled from said position for causing the connector switch to efiect connection rwith' the called line and the trunk switch to efle'c't connection with the selected connector switch, means controlled in the operation of the connector switch in selecting the called line to render it unselectable, means controlled by the calling subscriber through the trunk switch for rendering said connector switch selectable.

21. In a telephone exchange system, the combination with a connector switch, of a trunk switch for effecting connection therewith, means independent of said trunk switch for selecting said connector switch, means for operating said connector switch when so selected to render it unselectable, and means controlled by said trunk switch for again rendering said connector switch selectable by said independent means.

22. In a telephone exchange system, the combination with a plurality of connector switches, of a trunk switch, an operators position, means controlled from said position for selecting an idle one of said connector switches, means thereafter for operating the selected connector switch and for operating the trunk switch to cause it to become associated with the selected connector switch,

means controlled in the operation of the connector switch to render 1t unselectable, and means controlled b said trunk switch for again rendering sai connector switch selectable;

23. In a telephone exchange system, the combination with a calling and a called subsoribers line, of a link circuit, means for causing said link circuit 'to be associated with the calling line, a trunk switch associated with said link circuit, a plurality of connector switches for effecting connection with the called line, means for preselecting an idle one of said connector switches independent of said trunk switch, and means for associating the trunk switch with the preselected connector switch.

2st. In a telephone exchange system, the combination with a connector switch and a control relay therefor, of a trunk switch for effecting connection with said connector switch, means independent of said trunk switch for selecting said connector switch, meansfor operating said connector switch when selected to render it unselectable, means controlled by said trunk switch for operating said relay to render said connector switch again selectable.

25. In a telephone exchange system, the combination of a plurality of connector switches, a trunk switch for effecting connection with said connector switches, means separate from said trunk switch forselecting an idle one of said connector switches, and means controlled by the connector switch in'its operation to render said connector switch unselectable, and means controlled by said trunk switch for again rendering said connector switch selectable.

26. In a telephone exchange system, the combination of a'connector switch, a trunk switch for effecting connection with said connector switch, means separate from said trunk switch for selecting said connector switch, means controlled by said connector switch in its operation to render said switch unselectable, means controlled by said trunk switch for again rendering said connector switch selectable.

27. In a telephone exchange system, the combination of a connector switch, means for selecting said connector switch, a trunk switch, means for causing said trunk switch to be associated with said connector switch after its selection, means controlled in the operation of the connector switch for rendering said connector switch unselectable, and means controlled over said trunk switch for thereafter rendering said connector switch selectable.

28. In a telephone exchan e system, a plurality of connector switches, a trunk switch, means for selecting an idle connector switch independent of said trunk switch, means controlled in the selection of said connector switch for causing said trunk switch to effect connection therewith,means for causing the operation of said connector switch, means controlled in the operation of the connector switch to render said connector switch unselectable, means controlled through said trunk switch for again rendering said connector switch selectable.

29. In a telephone exchange system, the combination of a link circuit having a trunk switch permanently associated therewith, a plurality of connector switches, an operators position, means controlled from said position for automatically selecting an idle one of said connector switches independent of said trunk switch, means thereafter controlled from said position for causing the operation of said connector switch, and means also controlled from said position through said link circuit to operate said trunk switch to efiect connection with the selected connector switch, and means controlled in the operation of the connector switch 'for rendering said connector switch unselectable, and means controlled through said trunk switch for again rendering said connector switch selectable.

30. In a telephone exchange system, the combination of a plurality of connector switches, a trunk switch adapted to be conneet d i h; ny. n o said come to with h prese c e on ec i n w ch,

1-- .In e p on ex hang sys em, he combination of a connector s'witgh, a, trunk .switchiop effecting connection with said ,connegtor SWltQh, means independentof said trunk eh r. seleeting 'sie d conn ctor eeeeee swyqeh, 'fe eper ting aid. nn e 0 s w tqh when selectedjio render 1t unselect abl engl" means eo r l ed y ee d' t k" switch egeinej nder sa d n ell w c el'eeteble,

of'two iwitnesges. JQSEPHIi. WRIGHT;

nwth Pr senee W t ess s:

P ATS A I I I V v 

